// extsort.h
/**
* Copyright (C) 2008 10gen Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License, version 3,
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see .
*
* As a special exception, the copyright holders give permission to link the
* code of portions of this program with the OpenSSL library under certain
* conditions as described in each individual source file and distribute
* linked combinations including the program with the OpenSSL library. You
* must comply with the GNU Affero General Public License in all respects for
* all of the code used other than as permitted herein. If you modify file(s)
* with this exception, you may extend this exception to your version of the
* file(s), but you are not obligated to do so. If you do not wish to do so,
* delete this exception statement from your version. If you delete this
* exception statement from all source files in the program, then also delete
* it in the license file.
*/
#pragma once
#include "mongo/db/jsobj.h"
#include "mongo/db/diskloc.h"
#include "mongo/db/sorter/sorter.h"
namespace mongo {
typedef pair ExternalSortDatum;
/**
* To external sort, you provide a pointer to an implementation of this class.
* The compare function follows the usual -1, 0, 1 semantics.
*/
class ExternalSortComparison {
public:
virtual ~ExternalSortComparison() { }
virtual int compare(const ExternalSortDatum& l, const ExternalSortDatum& r) const = 0;
};
// TODO This class will probably disappear in the future or be replaced with a typedef
class BSONObjExternalSorter : boost::noncopyable {
public:
typedef pair Data;
typedef SortIteratorInterface Iterator;
BSONObjExternalSorter(const ExternalSortComparison* comp, long maxFileSize=100*1024*1024);
void add( const BSONObj& o, const DiskLoc& loc, bool mayInterrupt ) {
*_mayInterrupt = mayInterrupt;
_sorter->add(o.getOwned(), loc);
}
auto_ptr iterator() { return auto_ptr(_sorter->done()); }
void sort( bool mayInterrupt ) { *_mayInterrupt = mayInterrupt; }
int numFiles() { return _sorter->numFiles(); }
long getCurSizeSoFar() { return _sorter->memUsed(); }
void hintNumObjects(long long) {} // unused
private:
shared_ptr _mayInterrupt;
scoped_ptr > _sorter;
};
}